Bug 30825

Summary:

[CHROMIUM] Chromium/skia's canvas getImageData() is not accurate

Product:

WebKit

Reporter:

Stephen White <senorblanco>

Component:

Layout and Rendering

Assignee:

Stephen White <senorblanco>

Status:

RESOLVED FIXED

Severity:

Normal

CC:

eric

Priority:

Version:

528+ (Nightly build)

Hardware:

OS:

Windows XP

Attachments:

Description	Flags
Fix for data getImageData()'s unpremultiply	none
Fix typo	dimich: review+, commit-queue: commit-queue-

Stephen White

Reported 2009-10-27 09:17:30 PDT

Chromium/skia's implementation of canvas getImageData() does not unpremultiply colour values correctly. In particular, LayoutTests/fast/canvas/canvas-getImageData.html requires that premultiplied values retrieved from the canvas are accurately divided by alpha, but not rounded. See http://crbug.com/22700

Attachments
Fix for data getImageData()'s unpremultiply (2.22 KB, patch) 2009-10-27 09:22 PDT, Stephen White	no flags	Details Formatted Diff Diff
Fix typo (2.21 KB, patch) 2009-10-27 15:06 PDT, Stephen White	dimich: review+ commit-queue: commit-queue-	Details Formatted Diff Diff
Show Obsolete (1) View All Add attachment proposed patch, testcase, etc.

Stephen White

Comment 1 2009-10-27 09:22:23 PDT

Created attachment 41958 [details] Fix for data getImageData()'s unpremultiply

David Levin

Comment 2 2009-10-27 14:14:45 PDT

Comment on attachment 41958 [details] Fix for data getImageData()'s unpremultiply > Index: WebCore/platform/graphics/skia/ImageBufferSkia.cpp > + destPixel[1] = a ? SkColorGetG(color) * 255 / a : 0, I think you wanted a ";" here instead of a ",".

Stephen White

Comment 3 2009-10-27 15:06:52 PDT

Created attachment 41990 [details] Fix typo

WebKit Commit Bot

Comment 4 2009-11-09 17:25:27 PST

Comment on attachment 41990 [details] Fix typo Rejecting patch 41990 from commit-queue. Failed to run "['/Users/eseidel/Projects/CommitQueue/WebKitTools/Scripts/svn-apply', '--reviewer', 'Dmitri Titov', '--force']" exit_code: 1 patching file WebCore/ChangeLog Hunk #1 succeeded at 1 with fuzz 3. patching file WebCore/platform/graphics/skia/ImageBufferSkia.cpp Hunk #1 FAILED at 164. 1 out of 1 hunk FAILED -- saving rejects to file WebCore/platform/graphics/skia/ImageBufferSkia.cpp.rej

Eric Seidel (no email)

Comment 5 2009-11-09 17:30:35 PST

Looks like this was landed as r50408 but just not closed.

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